Heretofore, the economics of sack contained aerosols have been compromised by restrictions dictated by the least needed feature of a sack contained aerosol, said feature being the valve assembly retainment and sealing flange. Said flange is constructed to be mechanically and sealingly interlocked with the annular opening in the top of an aerosol can, fulfilling a necessary requirement for aerosols not provided with a product sack.
Three basic restrictions imposed on sack contained aerosols are filling, pressurizing and sack retainment. In existing art, at least one of the said restrictions is not satisfied in an economically feasible manner. Plugs are added for pressurizing, sacks are filled through valve stems and sack retainment relies on the valve assembly.
The applicant's U.S. Pat. No. 4,159,789 while recognizing permissive modifications to valve assemblies, neglected to utilize the sack for the introduction of the pressurizing agent and relied on the costly addition of a self-sealing plug.
The applicant's last co-pending application, Ser. No. 887,580, introduced a sack retainer. The sack retainer seemingly satisfied all said restrictions imposed by the valve assembly retainment and sealing flange. However, it, too, is an unnecessary cost item; and product overfill has a tendency of entering the pressure chamber portion of the container.
Other dispensers in the art having a collapsible sack are shown in the following United States Patents:
______________________________________ PATENT NO. INVENTOR ______________________________________ 3,549,058 E. J. Bolk 3,477,195 C. D. Chambers 2,816,691 L. T. Ward 3,731,854 D. E. Casey 3,169,670 P. Hrebernak & L. Zuckerman ______________________________________
None of the referenced patents economically satisfy all of the said imposed restrictions.
This invention is particularly suited for squeeze tube product containment sacks as described in the applicant's co-pending application, Ser. No. 887,580. However, it is fully recognized to have a broad application suitable for adaptation to all product containment sacks of said art. Therefore, this application is directed to a preferred embodiment.